Telecoils in hearing devices are to be replaced by long range radio-frequency (RF) based audio streaming systems at points of sale (POS) such as a ticket office, a bank, a post office, etc. It is possible to eavesdrop on such long range RF systems and therefore there may exist a privacy issue with such systems.
WO 2011/0015675 discloses a system for providing hearing assistance to a user, comprising at least one audio signal transmission unit comprising an audio signal source, typically a microphone arrangement, and means for transmitting audio signals from the audio signal source via a wireless radio frequency link to a left ear receiver unit worn at the user's left ear and a right ear receiver unit worn at the user's right ear.
US 2004/0208324 discloses a directional audio delivery device for an audio system. The audio delivery device provides directional delivery of audio output for the audio system. The generated audio output is substantially confined in one or more beams, each with a beam width. The output is targeted to one or more persons who would like to hear the audio output.
US 2004/0179510 discloses a communications method including the steps of: activating a plurality of signal sources, and transmitting a synchronization event to the plurality of signal sources to cause the plurality of signal sources to simultaneously transmit data in response to the synchronization event.
Thus, there is a need to provide such long range systems configured for secure streaming of audio data between a point of sale and a hearing device.